1. Field of the Invention
This invention relates to a method and apparatus for producing and dispensing aerated and/or blended food products. While the invention may be used to produce a variety of products, it has particular application to the production and dispensing of frozen confections such as ice cream and frozen yogurt. Consequently, we will describe the invention in that context. It should be understood, however, that various aspects of the invention to be described also have application to the making and dispensing of various other food products.
2. Description of the Prior Art
Aerated frozen food products generally require the mixing of selected liquid ingredients with a prescribed volume of air and freezing of the resultant mixture and dispensing of the finished product. The desirability of the finished product is often related directly to the manner and to the degree in which the air is metered and blended with the liquid ingredients of the mixture, referred to as overrun, and the manner in which the blended mix is frozen and then dispensed. The prior art is replete with examples of apparatus for dispensing ice cream and other semi-frozen dairy products such as soft ice cream and frozen yogurt.
Conventionally, such machines are usually dedicated to dispensing one or two flavors of product and, in some cases, a combination of the two. For example, in an ice cream shop, there may be one machine with two separate freezing chambers for making and dispensing chocolate and vanilla ice cream, a second two-chamber machine for making and dispensing strawberry and banana ice cream, a third machine dedicated to making and dispensing coffee and frozen pudding flavors, and so on. The reason for this is that each chamber typically contains a volume of ice cream greater than is required for a single serving. In order to dispense a different flavor ice cream, that chamber must be emptied and cleaned before the new flavor can be made in that chamber and appear at the outlet of the dispenser. Additionally, the vat of preflavored mix from which the frozen product is made must also be very clean. While high volume ice cream shops and confectionery stores may have sales to justify the presence of several dispensing machines dispensing many different products and flavors, smaller sales outlets can usually only afford one or two such machines and are thus restricted in the number of flavors that they can offer to customers.
Further, because the product is typically formed in a quantity that is greater than that to be dispensed at any one serving, the excess product remains in the chamber after formation and until additional servings draw it down. The excess is thus subjected to further freezing which promotes crystallization. Because of the relatively large quantity of the premixed flavors, and the continuous freezing of several quarts of the product, the freshness and palatability of the product may be adversely affected in outlets with relatively slow sales of the product.
Another disadvantage of the prior dispensers is that they have many interior surfaces and moving parts that are difficult and time consuming to clean and maintain at the end of each day or at intervals prescribed by local Health Departments regulations. Each dispenser must be purged of any remaining product, and it""s chamber walls, pumps and other internal parts cleaned thoroughly to prevent growth of bacteria that could contaminate the product being delivered by the dispenser. Not only is the cleaning operation expensive in terms of down time, it is also costly in terms of product waste and is an unpleasant and difficult job to get employees to do properly.
U.S. Pat. No. 5,433,967 discloses a method and apparatus for producing and dispensing an aerated product which includes a mixing chamber having a first inlet for receiving a liquid, a second inlet for receiving a gas, and an outlet leading to a continuous tube which has a relatively small cross section. The tube has one end positioned to receive the fluid effluent from the mixing chamber outlet and its other end is spaced from that outlet so that the effluent is subjected to confined turbulent mixing in the tube until the fluid product is discharged from the other end of the tube. If that product is to be cooled, the tube leads to a cooling zone or surface which cools and at least partially freezes the liquid product issuing from that tube. The apparatus disclosed there is especially suitable for making and dispensing frozen yogurt and ice cream and allows for the service of individualized fresh product portions in a variety of flavors.
U.S. Pat. No. 5,727,713 discloses a dispenser product supply unit which includes a pressurizable container for containing a product liquid or base and having an opening leading into one end of a conduit. Formed integrally in the conduit is a mixing chamber at which a gas may be added to the liquid, followed by an elongated tube for causing turbulent flow of the mixed fluids. Side branches from the conduit may also be present for introducing one or more flavors into the fluid flowing through the conduit. The opposite or outlet end of the conduit may be coupled to a distribution manifold that can distribute the aerated liquid issuing from the turbulence tube onto a freezing surface as a relatively thin layer. The container, conduit and side branches constitute a one-piece disposable structure which is especially suitable for producing and dispensing flavored dairy products from an associated dispensing apparatus in an efficient and sanitary manner.
While the apparatus described in the above patents, the contents of which are hereby incorporated herein by reference, have existed separately in the prior art, until now no way has been found to combine them into a single machine capable of efficiently and economically making and dispensing different frozen food confections in a wide variety of flavors and in different formats, e.g. as a cup or cone.
Accordingly it is an object of the present invention to provide improved apparatus for making, mixing and/or dispensing various food products on demand.
Another object of the invention is to provide apparatus for producing and dispensing various food products which does not require the maintenance of a large supply of preflavored mixes and/or a large supply of finished product within the apparatus.
Still another object in the invention is to provide such apparatus which facilitates changing substantially immediately from one product type to another to satisfy the demands of individual customers.
A further object of the invention is to provide apparatus for producing and dispensing individualized portions of freshly aerated flavored frozen products on demand and in different formats, e.g. as a cup or cone.
Yet another object of the invention is to provide apparatus for producing and dispensing aerated frozen products which is easy to clean and to maintain in a sanitary condition.
Another object is to provide apparatus for selectively mixing or blending many different flavors while aerating a base product such as a neutral ice cream, fat-free ice cream, soy, sorbet or yogurt base.
An additional object is to provide a frozen product-dispensing machine which has a minimal product carryover from one serving to the next, e.g. which prevents a serving of vanilla ice cream from being contaminated by residue from a prior serving of chocolate ice cream.
A further object of the invention is provide apparatus for this general type which occupies a relatively small amount of floor space while being able to dispense food products having a wide variety of bases, flavors and mix-ins.
Still another object of the invention is to provide apparatus of this type which maintains the product supply under sanitary conditions until it is dispensed.
A further object of the invention is to provide apparatus for effectively and efficiently carrying out the dispensing methods disclosed in the above patents.
Yet another object of the invention is to provide a method of producing and dispensing various food products which produces one or more of the above advantages.
Other objects will, in part, be obvious and will, in part, appear hereinafter. The invention accordingly comprises the several steps and the relation of one or more of such steps with each of the others, and the features of construction, combination of elements and arrangements of parts which will be exemplified in the following detailed description, and the scope of the invention will be indicated in the claims.
Briefly, our product dispensing apparatus is preferably a self-contained unit housed in a cabinet having a door containing a product selection control panel and a portal providing access to a product dispensing station including a vertically moveable tray which can support a product container such as a cup or cone placed on the tray. The apparatus includes a rotary horizontal freezing surface and motive means for rotating that surface about an axis. The freezing surface constitutes the evaporator component of a closed-loop refrigeration system situated in the cabinet. When the refrigeration system is in operation, it maintains the surface of the freezing surface at a selected temperature which is low enough to freeze or partially freeze a liquid product mix such as sorbet, yogurt or ice cream mix deposited on that surface.
Spaced above the freezing surface is a turret section including a turret having a plurality of pumpable containers filled with different liquid flavors and supported on a rotary manifold. The manifold defines a plurality of mixing chambers, one for each container, and a separate turbulence tube leading from each mixing chamber to a separate outlet port in a depositing head over the freezing surface. Each container is connected to one of the mixing chambers of the manifold and motive means are provided for rotating the turret independently of the freezing surface, about an axis located above the freezing surface.
Disposed adjacent to the turret are product base delivery means including one or more vertically moveable nozzles or fittings each of which receives compressed air and a different one of a plurality of liquid product bases pumped thereto from bulk supplies stored in the cabinet. Each of the aforesaid nozzles, when operative, may deliver to the turret a liquid product base along with air (or not). By rotating the turret to position a selected mixing chamber of the manifold opposite a selected one of the delivery means nozzles, and lowering the nozzles to establish connections to that chamber while activating appropriate pumps, the selected product base with or without air delivered by a nozzle is brought together with the selected flavor pumped from a flavor container. The two fluids are then intimately mixed together in the manifold and conducted to the manifold""s depositing head so that a fixed volume or portion of the selected flavored and aerated (or not) product mix is deposited on the freezing surface.
The apparatus also comprises a stationary product delivery section disposed between the turret section and the freezing surface. The delivery section has product mix leveling means in the form of a radially oriented self-cleaning roller having a conical surface spaced above the freezing surface. When the freezing surface is rotated, the liquid product mix deposited thereon by the turret section is spread out and leveled to the height of the gap between the roller and the freezing surface. Resultantly, the surface freezes or partially freezes the leveled product mix to form a thin, flat layer of frozen, flavored, aerated (or not) product. The delivery section also includes a radial scraper angularly spaced behind the roller which scrapes the layer of frozen product from the rotating freezing surface and gathers it into a radially extending ridge row of frozen scrapings which row is aligned with a vertically oriented forming cylinder located at the periphery of the delivery section just beyond the edge of the freezing surface.
The delivery section also has a radially moveable scraping blade which operates in conjunction with the radial scraper to push the ridge row of frozen product through a side window of the forming cylinder to gather and compress the frozen product within that cylinder. As will be seen, when the scraping blade is fully extended, it actually closes the window in the cylinder allowing a piston moveable along the cylinder to further compact the product into a scoop shape and push the scoop of frozen product out the bottom of the cylinder into a container, e.g. a cup or cone, which has been placed on the tray at the product dispensing station and raised to position the container at a selected elevation under the forming cylinder. After the container is filled, the tray is lowered so that the container may be removed from the tray through the portal in the cabinet door.
As will be described in more detail later, provision is made for cleaning the freezing surface, leveling roller, forming cylinder and piston between servings to minimize product carryover from one serving to the next. Also as will become apparent, the apparatus is designed so that all critical components of the apparatus are readily accessible for cleaning and routine maintenance. Thus, the present apparatus is able to efficiently and effectively dispense, on demand, a variety of food products for a prolonged period of time and requires only a minimum amount of maintenance.
It should also be understood that various aspects of the invention may be used to mix, blend and dispense various other hot or cold food products such as hot chocolate, instant soups, juices and even candy, cookies, omelets, crepes and the like.